The invention relates generally to an optical article for playback in a player. More particularly the invention relates to providing an optical article with a customized player-readable code printed on the optical article that allows for customization and/or enhancing the security of the optical article and the data contained in the optical article.
A variety of methods have been tried in the art to provide optical media with unique identification codes. One such method includes a bar code known as a burst cutting area (BCA) which may be individually written to each replicated optical media. The bar code may be created by a very powerful laser that burns and darkens the reflective metal layer in the center of the bonded optical media, e.g., a DVD, yielding marks with decreased reflectivity. Because there is no player specification, the player would not need a support for reading the bar code. There is, however, a requirement for DVD-ROM drives to support the Mount Fuji specification, which includes a provision to read bar code information within the “read disc info” command. With the exception of the DIVX format, DVD Video players do not read BCA. Further, there are only a few DVD manufacturers equipped to write the bar codes on replicated discs. For these reasons, the universal application of BCA to give a disc a “unique ID” or to implement the BCA for enhanced security as described in this disclosure may not be very practical. In addition, there is no way to link logical decisions or authoring on the disc to the code contained in the BCA. Thus the content on the disc that is displayed during playback may not be customized through use of the BCA.
In certain cases, regional codes installed in the players themselves are checked during disc playback. The original idea behind this was to restrict playback of discs in certain regions of the world. In theory, a disc could be programmed to customize the content based on the regional code detected in the player during playback. In practice this is difficult because the regional codes are very coarse grained (5 regions worldwide), player compatibility to regional code readout is less than optimal, and there is no general control over movement of DVD players throughout regions. In addition, regional codes may often be altered in the players. In practice, regional codes are seldom used to customize content.
Also, there have been other efforts to serialize optical media for copy protection and/or digital rights management. A notable application of this technology is used by Microsoft for the “Product Activation” process for protecting computer software. In this method a laser may be used to burn additional data (Unique IDs) into the data spiral of optical discs. Certain other methods include incorporation of pits and lands on a disc that may be modified to create errors and the subsequent location of these errors can be translated into a unique serial number. Also CD-ROM encryption systems have been described where the information on a CD-ROM is encrypted by a key. The key may be programmed into the CD-ROM after manufacture by damaging selected sectors to be unreadable by conventional read systems. The selected sectors may be physically damaged by a high power laser. Another method includes a novel optical disc made by molding a dye-doped polycarbonate resin and marking marks of specific size and location into the polycarbonate substrate of the disc using a laser. Also, software detection methods for reading the unique identification codes from the disc have been disclosed for computer drives. These serialization techniques require some type of external software or firmware and are not practical on DVDs because the players would need to be modified.
Accordingly, there remains a need for an improved solution to the long-standing problem. The method described herein fills this need by employing a printing and authoring method that will permit the introduction of customized player-readable identification codes on the optical articles that can be read by using available readers without the need for specialized software or modified drive firmware wherein the authoring may be linked to the code.